Pipe thread protector



B. ENGSTROM PIPE THREAD PROTCTOR Nov. 26, l1935.

Filed March 29, 1935 FIG. .9.`

v. A n

Fla. 1o.

INVENTOR WITNESSES Patented Nov. 26, 1935 UNITED STATES PATENT OFFICE 2,022,189 PIPE THREAD PROTECTOR Birger Engstrom, Pittsburgh, Pa. i

` Application March 29, 1935, Serial No. 13,661

13 Claims.

This invention relates 'to an improvement in thread protectors of the type used t'o prevent the threads on the ends of tubes, shafts, rods and the like, from being damaged While they are being handled, coated or shipped from one place to another. While quite a great number of different kinds of protectors of this character have been developed and used, there is still considerable room for their improvement, and it-is towards the reduction of vtheir cost, their serviceability and -the ease and convenience of their use that this invention is more particularly directed.

It is another of its objects to provide a protector which can be used on tubular articles without its interfering with the handling of the articles and which, at the same time, is adapted to seal the interior of the articles against the admission of any liquids or foreign matters, which is, for many purposes, ,highly desirable.

It is also one of its objectsto provide a protector-which does not depend upon positive engagement between it and the threads being protected for its installation, and which, while held in place when applied in a most effective and dependable manner, is adapted Vto be applied and removed by most simple. and easy operations.

A further object is to provide a protector which 1, 2 and 3 are views partly in elevation and part- 1y in section of three different modifications of one form of an outside thread protectorl embodying the invention; Figs. 4 and 5 similar views of two modications of the same form of the invention designed to y,protect the threads on the inside of a pipe; Figs.'6 and '7 similar views of two modications of another form of the invention designed for outside thread protection; Fig. 8 a similar view of an inside thread protector embodying the form of invention shown in Figs. 6 4and '1; Fig. '9 an end view of the protector shown in Fig. 1'; and Figs. 10 and 11 perspective views, respectively, of an outside and an inside clamping ring, such as are used in the forms of the invention illustrated in Figs. 1, 2, 3, 4 and 5.` Referring to the drawing, the numerals I and of the 'invention and, while they represent the problem involved in its most common form, it is'to be understood, as will be readily apparent, that the invention may be applied to any kind of end-threaded annular article.

In accordance with the .invention as illustrated in Figs. l, 2 and 3, an exterior thread protector is provided comprising a soft composition e or fabric liner 3 which is placed around the article over the threads 4 to be protected. Outside of this liner there is mounted a relatively thin cup-shaped casing 5 which is either split along its side or provided with a plurality of slits 6 in its vlower end which allow it to expand and hence permit its being easily and readily slid onto the l5 ing 5 there is telescopically mounted a sturdy'20 clamping ring 'I which is tted tightly onto the casing and preferably extended over the entire length of the threads for their protection, al-

though its width may be considerably varied, and where ya narrow ring is used the casing 5 may be 25 increased in weight where needed. l

The soft liner/3, which is placed next to the thread, is made of some such material as felt, composition packing, rubber, or other suitable yielding material, and either wound thread or applied in the form of a split or a. complete ring either before or with the encasing member 5. The casing 5, which encases this liner, is used principally merely for the purpose of making it possible to readily slide th clamping ring 1 in place, clamping the liner firmly against the threads without the latter damaging or disturbing the liner when it is moved into place. l'

As is common knowledge, the threads are usually out on a progressively varying diameter or taper, and this is made use of in clamping the protector onto the threads. To take advantage of such condition the liner supporting casing 5 is preferably made with an inside diameter substantially equal to the outside diameter of the liner 3 at its outer end, and either split or slotted l at its inner end as previously referred to, so that as it is slid onto the pipe over the liner it will readily expand and allow it to into position. The clamping ring l" in turn is made with an inside diameter which is only sufliciently greater than the outside diameter of the casing 5 to 'permit it to be readily moved over the outer end thereof but suiciently close there- 55 about the 30 be easily moved 50 to that as it is forced onto the end of the pipe a wedging action takes place which, due to the collapsibility of the casing 5 and the taper of the threads, causes the liner 3 to be firmly jammed into the threads 4 and the protector rigidly secured in operative position.

To adapt the protector to seal the end of the pipe, as well as to' protect the threads so that no vliquids or other foreign matters canvget into it when the protector is applied, the casing 5 is provided with a totally enclosed outer end portion which may be either plain as shown in Fig. 2 or indented at its center as shown in Fig. 1 to permit the use of hooks, or other means, for handling the pipes as is commonly done, particularly in the handling of large pipes. Another advantage of such indentation of the end of the casing 5 is that it makes it possible to use an ordinary wrench for unscrewing the coupling as the Wrench can then be simply applied to the end `of the protector and the assembly removed as a whole. v

When the protector is used with pipes which d o not require the sealing feature, or in which it is desired to hold'its cost as low as possible, the

interlining casing 5a is made as shown in Fig. 3 in the form of a split collapsible ring having its outer end turned in to form a sufficient flange to engage the end of the pipe. Such an element, as will be apparent, will suilice to-protect the liner 3 and vis-quite a little cheaper'to make than the other forms shown. Y

While a welded or any other suitably manufactured solid clamping ring l may be employed as the outside clamping and thread-protecting element of the protector, a form which hasbeen found to be particularly desirable for this purpose is that shown in Fig. 10. As shown in this figure, a split ring is provided which has its ends connected together by interlockingdovetail shaped lugs 1a which, for all purposes and effect,

hold them together just as well as a weld.

Among the advantages of this form of ring, it is cheaper to manufacture and can be readily removed merely by disengaging the lugs, which simplifies the removal of the protector as it does vaway with the need of sliding it oil! the endof the pipe, and when removed it relieves the pressure on the casing and liner. To facilitate the dislodging of the interlocking lugs 1a, an opening y1b is provided in one end of the band forming the ring, and preferably in the center thereof adjacent one ofthe lugs 1a, and made sufficiently large to receive'a screw-driver or similar tool which may be used for separating the lugs. As a safety'feature to insure against any accidental .dislodgment due to jarring of these lugs in service they may be spot welded at one or more points 1c. Thiswill hold them quite firmly together and at thesame time permit the band to be separated quite readily by a forcing tool..

To insure against any possibility ofthe c1amp" ing ring llbeing slid from the end of the protector while the pipe is being handled', beads or-.other equivalent means II) (shown in -their normal shape in Fig. l) may be provided at-the end of the casing 5 about its periphery and adapted to be hammered out after the protector is applied (as shown in Fig. 2) so that the metal is displaced in a manner to form lugs which engage the outer en ds of the clamping ring 1 and thereby prevent its being slid outwardly. Such construction is particularly desirable where clamping rings of the type Shown in Fig. 10 are used and which, as will be readily appreciated,=-do not have to V protector.

To adapt the invention for protecting threads on the inside of a pipe asillustrated 'in Figs. 4 and 5, the pliable thread-engaging liner 5 is 5 made to ilt on the inside of the pipe and the cup-shaped liner protecting casing II is made to fit inside of it as is the clamping ring I2 which is wedged in 'thecasing I I in the same fashion that the ring 'I is wedged on the outside 10 thread protector previously described.

As in the outside protector, the interlining casing II is either slotted as shown in Fig. 4 to permit it to collapse, or is made in the form of an interrupted ring as shown in Fig. 5 for the, same 15 purpose. As also shown in Figs.-4 and 5, it may be made with either yan enclosed inner end for sealing purposes or without an enclosed inner end to cheapen its cost. Also, the clamping ring I2 may be either made solid as shown in Fig.l 5 or in zo the form of a split ring as shown in Figs. 4 and 11. When the latter form is used, it, like thering 1, is preferably provided with an opening I2a adjacent its lugs I2b for receiving a tool for dislodging the lugs, andsuch opening is prei'- 25 erably disposed at the outer edge of the ring to v facilitate the receptionrof the stripping tool.

Another way of practicing the invention is i1- lustrated in Figs. 6, 7 and 8. As shown in the first two of these figures, which illustrate outside 3 thread protectors, the clamping ring I3 instead of the interlining liner protecting casing I 4 is adapted to providethe end-enclosing seal for the pipe, and like the casing 5 in the previously described coupling, is made in the shape of a cup and with 35 either a plain or an indented end wall as may be desired. The soft liner I5 is the same as previously described, while the interlining casing I4 is made in the shape of a simple interrupted ring or band which allows it to be readily applied and 40 removed.

To protect the interior threads of a pipe in accordancev with the latter form of the invention as shown in Fig. 8, the assembly shown in Figs. 6 and 7 is merely inverted to nt on the inside instead of on the outside of the pipe.

As will be readily appreciated by those skilled in the art, this invention provides a protector j which is simple and relatively inexpensive to .next driven into place until the protector is rigidly secured to the threaded member. Where ythe beads I0 are provided on the protector for locking the clamping ring in place, they are flattened as soon as the ring is in position. To remove the protector the entire assembly may be vunscrewed altogether due to the engagement of the threads in the soft liner, or the clamping ring or clamping member may be removed separately as pointed out and the casing and soft liner then 7o either stripped or turned from the threaded portion `of the article.

According to the provisions of the patent statutes, I have explained theprinci'ple and construction of my invention, and have illustrated and u described what il now consider ,to

nt its best embodiments. owever, I dre to ve it understood that, within the scopeoi the appendn ed claims, the invention y be practiced otherwise than as specically illustrated l and described.

I claim:

l. a thread protector comprising a liner of soft material disposed to cover the threads to be protected, an expansibly yieldable casing disposed to extend over and protect the surface of said liner opposite the threads and entirely out of contact with said threads, and a clamping ring telescoplcally press tted over said casing in a manner to embed the threads in said liner and rmly hold the assembly in place.'

2. A thread protector comprising a liner of soft material disposed to cover the threads to be protected, an 'expansiblyvyieldable casing having a closed outer end disposed to fit over and protect the surface of said liner when the protectory is being assembled and entirely out of contact with the threads, and a rigid protecting sleeve which is telescopically press tted over said casina in such a way as to embed the threads in the liner' and tightly clamp the assembly onto the threaded surface.

3. A thread protector comprising a liner oi soft material which lies adjacent to and extends over the threaded surface, a cup-shaped metallic casing having expansion slits in its side wail mounted over and encasing said liner, and a clamping ring engagingsaid casing in such a manner as to force the soit liner into the threads and rmly ing protected.

5. A protector according to cla 1 in which the clamping member is made in the shape of a cup.

'6. VA protector according to claim 1 in which the expansibie casing consists oi a split ring pro- 5 vided at one end with a turned edge for limiting its movement into the article being protected.

7. A protector according to claim l, in which a clamping element is employed which comprises a split ring the ends of which are releasably con- 10 nected together hy an interlocking lug arrangement. ,i

8. A protector according to claim 1, in which a clamping element is employed which comprises a. split ring the ends oi-which are releasably con- 15 a clamping element is employed which comprises a split ring the ends of which are releasably held 25 together.

1l. A device for protecting threads on the inside of a hollow article at the end thereof comprising a soft liner disposed to lie adjacent to and cover the threads to be protected, an ex- 3o pansihiy yieldahle surface protecting casing arranged adjacent the inner surface oi said liner, and a clamping member tted inside of said casing to hear thereagainst and force said liner into the threads and hold the assembly in place. 35

l2. A protector according to claim ll, in which the liner protecting casing is made in the shape of a cup provided with expansion slots in its side wall.

13. A protector according to claim ll, in which lo the liner encasina casing is made in the shape or a split ring d the .mi member in the shape of a cup. 

